However, the deal does not include the US and analysts are speculating whether US shale producers step into the breach and help keep a lid on prices.

FXTM's chief market strategist Hussein Sayed says in an email on Monday morning: "Now with 1.758 million barrels expected to be slashed out of the market, or about 2% of the global oil supply starting January 1, oil prices have more room to rally with Brent potentially crossing above $60 in the next couple of weeks.

"The market's focus will then switch to compliance with the agreement, and US shale producers who are not a part of the agreement. US rig counts rose by 21 last week to 498, the biggest increase since mid-2015, and the questions now becomes how fast will US shale ramp up production and at what level is it possible to cap the current rally?"

Fawad Razaqzada, a market analyst at Forex.com, says in an email on Monday morning: "It is very likely that US shale producers will take advantage of this opportunity to ramp up their crude output once again but this will be a worry for another day."

But Tony Cross, a market analyst at TopTradr, is more cautious. He says in an email: "On the basis that legislation has been changed to permit exporting of US oil, the potential upside would seem to be limited - although many oil producing nations will certainly be comfortable with crude closing out the year around the $55 level."

Goldman Sachs isn't upgrading its long-term oil price forecasts because of US shale, saying in a note on Sunday: "We expect that a greater producer response, especially in the US, would eventually bring prices back to $55/bbl."

Michael Hewson, chief market analyst at CMC Markets, says in an email on Monday morning: "With US prices also following suit the big question now is whether the shale producers start to bring dormant production capability back on line."